Results 1 to 8 of 8

Thread: My Gaggia Classic PID Mod

  1. #1
    Senior Member
    Join Date
    Nov 2004
    Location
    Brisbane, Australia
    Posts
    126

    My Gaggia Classic PID Mod

    Gene Cafe Coffee Roaster $850 - Free Beans Free Freight
    Ive finally fitted PID to my Gaggia Classic 8)


    The mod is very simple & didnt require any modification of the classics SS case so it can be returned to normal operation with a little effort.

    This PID controller has an event input which I use to select a second set point & PID values for steam. Ive utilised the original steam switch in the gaggia to activate this.

    All works quite well so far.

    For the mod I used the following Parts:

    - Brain Child BC9300 PID controller
    - K type thermocouple (hand some spare)
    - Thermocouple (had some k type handing about)
    - Solid State Relay (SSR)
    - Plastic Project Box
    - Fuse holder & Fuse
    - Quality Double sided tap
    - Heat shink
    - Cable ties

    Lets pop the hood and take a look inside



    And from the back



    Close up of front




    More details and a circuit diagram will follow soon.

  2. #2
    ed_vinas
    Guest

    Re: My Gaggia Classic PID Mod

    Nice work hv_man. ;)

    How have you found the shots produced so far?

    Cheers
    Ed

  3. #3
    Senior Member
    Join Date
    Nov 2004
    Location
    Brisbane, Australia
    Posts
    126

    Re: My Gaggia Classic PID Mod

    Yes Ive found my shots to be more consistant. ;D
    Being able to vary the temperature also helps to tune them in.
    I use to get some very bitter :-X ones I put down to high temp, this mainly happen when I let it warm up for say 1/2hr, pull a couple blanks into the cups to warm them up and then proceed to pull a double, I though I was doing the right thing by letting every thing warm up etc....., however now I believe this was at to high a temperature, as I now can leave it on for hrs without any problems.

    I got very frustrated ??? with temp surfing could never seem to get it right this eventually drove me to the PID mod.

    The stock thermostat in the Classic is set to 107deg C.
    Ive been experimenting @ 96Deg C, IMO an improvement shot quality, still playing..... 8)

    Very happy so far.

  4. #4
    Senior Member
    Join Date
    Apr 2005
    Posts
    1,176

    Re: My Gaggia Classic PID Mod

    Very nice work.

    Variability in shot quality with the classic is also starting to annoy me. Im also thinking of a PID mod. How do you rate the conversion thus far?

  5. #5
    Senior Member
    Join Date
    Nov 2004
    Location
    Brisbane, Australia
    Posts
    126

    Re: My Gaggia Classic PID Mod

    Im very happy with the mod.

    My only problem is when coming down from steaming it takes some time to restablise the temperature, Im sure this is a tuning problem (use 2 PID setting).
    Unfortunately havent had time to play/fix it.


  6. #6
    Senior Member
    Join Date
    May 2004
    Posts
    439

    Re: My Gaggia Classic PID Mod

    Can you give a supplier/part no listing?
    Does a cooling flush after steaming help the temp restablising?

    Greg

  7. #7
    Senior Member
    Join Date
    Nov 2004
    Location
    Brisbane, Australia
    Posts
    126

    Re: My Gaggia Classic PID Mod

    Hi Greg

    Yep the flushing helps but I really have to get of my backside and play with the tuning.

    Ill put up a parts list soon.


  8. #8
    Senior Member
    Join Date
    Apr 2005
    Posts
    1,176

    Re: My Gaggia Classic PID Mod

    Behmor Brazen - $249 - Free Freight
    Rather than start another thread, I thought Id add that I have just finished the PID mod on my Classic.... ;D

    If I were to describe the effects of the mod, Id say its like the going from driving a car with your eyes shut to with your eyes open. It makes a huge difference in shot quality, stability and tunability and repeatability. Furthermore, the mod can actually control the temperature during the shot to less than 0.5 deg C fluctuation. Thats not the actual water temp though, just the boiler temperature. Nevertheless, without PID control the boiler temperature fluctuation during the shot is huge. In actual use stratafication of the incoming cold water ameliorates this effect somewhat, but active PID control can actually improve it. One of the benefits of the Classics small boiler and external element is that the thermal time constants are really small allowing thermal control DURING the shot.

    Bottom line is I have already been able to tune my shots from bitter to sour (keeping grind and tamp constant) in only my first morning. I look forward to dialling in the machine to the exact beans Im using, especially the fresh beans that arrived yesterday :-*

    One more good thing is that, as my machine is still under warranty, all the mods are completely reversable, so it can easily be restored to original condition without any tell-tale signs of tampering.

    Next mod is to set the over-pressure relief valve to 9 BAR to cap my brew pressure, then... in the distant future... preheating the incoming water... PID heating collar on the group... I find the Classic to be an excellent machine for tinkering.



Similar Threads

  1. Replies: 6
    Last Post: 15th March 2012, 09:20 PM
  2. Replies: 4
    Last Post: 10th December 2011, 12:23 PM
  3. Gaggia Classic portafilter and GAGGIA PROTEO ROMANZA
    By cazby in forum Brewing Equipment - Midrange ($500-$1500)
    Replies: 0
    Last Post: 24th October 2011, 06:50 PM
  4. Replies: 6
    Last Post: 23rd November 2009, 07:19 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •